Add ipwhois library + dependencies

lib/dns/wiredata.py

@@ -0,0 +1,84 @@
+# Copyright (C) 2011 Nominum, Inc.
+#
+# Permission to use, copy, modify, and distribute this software and its
+# documentation for any purpose with or without fee is hereby granted,
+# provided that the above copyright notice and this permission notice
+# appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND NOMINUM DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL NOMINUM BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
+# OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+"""DNS Wire Data Helper"""
+
+
+import dns.exception
+from ._compat import binary_type, string_types
+
+# Figure out what constant python passes for an unspecified slice bound.
+# It's supposed to be sys.maxint, yet on 64-bit windows sys.maxint is 2^31 - 1
+# but Python uses 2^63 - 1 as the constant.  Rather than making pointless
+# extra comparisons, duplicating code, or weakening WireData, we just figure
+# out what constant Python will use.
+
+
+class _SliceUnspecifiedBound(str):
+
+    def __getslice__(self, i, j):
+        return j
+
+_unspecified_bound = _SliceUnspecifiedBound('')[1:]
+
+
+class WireData(binary_type):
+    # WireData is a string with stricter slicing
+
+    def __getitem__(self, key):
+        try:
+            if isinstance(key, slice):
+                return WireData(super(WireData, self).__getitem__(key))
+            return bytearray(self.unwrap())[key]
+        except IndexError:
+            raise dns.exception.FormError
+
+    def __getslice__(self, i, j):
+        try:
+            if j == _unspecified_bound:
+                # handle the case where the right bound is unspecified
+                j = len(self)
+            if i < 0 or j < 0:
+                raise dns.exception.FormError
+            # If it's not an empty slice, access left and right bounds
+            # to make sure they're valid
+            if i != j:
+                super(WireData, self).__getitem__(i)
+                super(WireData, self).__getitem__(j - 1)
+            return WireData(super(WireData, self).__getslice__(i, j))
+        except IndexError:
+            raise dns.exception.FormError
+
+    def __iter__(self):
+        i = 0
+        while 1:
+            try:
+                yield self[i]
+                i += 1
+            except dns.exception.FormError:
+                raise StopIteration
+
+    def unwrap(self):
+        return binary_type(self)
+
+
+def maybe_wrap(wire):
+    if isinstance(wire, WireData):
+        return wire
+    elif isinstance(wire, binary_type):
+        return WireData(wire)
+    elif isinstance(wire, string_types):
+        return WireData(wire.encode())
+    raise ValueError("unhandled type %s" % type(wire))